Effect of initial microstructure on the micromechanical behavior of Ti-55531 titanium alloy investigated by in-situ high-energy X-ray diffraction

Journal Article · 09 December 2019 · Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing

DOI: https://doi.org/10.1016/j.msea.2019.138806 · OSTI ID:1618118

Cui, Yimin ^[1]; Li, Chaohua ^[2]; Zhang, Changsheng ^[3]; Li, Runguang ^[2]; Ren, Yang ^[4]; Zheng, Weiwei ^[2]; Wang, Yan-Dong ^[2]

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1. Univ. of Science and Technology Beijing (China); China Academy of Engineering Physics, Mianyang (China)
2. Univ. of Science and Technology Beijing (China)
3. China Academy of Engineering Physics, Mianyang (China)
4. Argonne National Lab. (ANL), Argonne, IL (United States)

Microstructure features including the morphology and texture of constituent phases play an important role in the mechanical properties of Ti-55531 high strength titanium alloy. However, the underlying understanding from the micromechanical aspect is still lacking. In the present work, the effect of microstructure on the micro-mechanical behavior of Ti-55531 alloy was investigated by high-energy X-ray diffraction. For two typical microstructures of Ti-55531 alloy, the micromechanical behavior including lattice strains of oriented grains are determined. Furthermore, the stress partitioning between alpha and beta phase and internal microstress evolution in the specimens with different microstructures are discussed. In combination with the microstructure characterization, the corresponding mechanism for microstructure influence on the mechanical properties is discussed. It is found that, for the specimens with different types of microstructures, stress partitioning between constituent phases is obviously different. The results show that the alpha phase stress is higher than that of p phase in the specimen with the bimodal microstructure (BM), while the beta phase is subjected to much higher stress than a phase in the specimen with the lamellar microstructure (LM). For the specimen with BM, the morphology of alpha phase leads to a remarkable difference in the microscopic deformation behavior between alpha(p) (primary alpha phase) and alpha(s) (secondary alpha phase). It is suggested that the acicular alpha(s) precipitates bear higher stress than equiaxed alpha(p). The intergranular and interphase microstresses in both specimens have been quantitatively evaluated. The results show that the < 200 >//LD fiber texture of beta phase leads to higher intergranular microstress in the specimen with BM. The interphase microstress is more remarkable in the specimen with LM. Combining the in-situ HEXRD and microstructure characterization, the present study provides a fundamental understanding of the relationship between microstructure and mechanical properties from the perspective of micromechanical behavior.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Key Research and Development Program of China; USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Scientific User Facilities Division
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1618118
• Journal Information: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing, Journal Name: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing Journal Issue: C Vol. 772; ISSN 0921-5093
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English